Compressor

ABSTRACT

A compressor includes a housing having a hollow projection portion, a rotary shaft provided rotatably within the housing, a piston reciprocating in accordance with rotation of the rotary shaft for sucking and discharging refrigerant, a bearing disposed within the projection portion of the housing for rotatably supporting one end of the rotary shaft and an attaching leg portion formed on an outer surface of the projection portion of the housing. The attaching leg portion is fastened to an engine block, a bracket or the like by using a bolt or the like.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a compressor, and more particularly, to a reduction of vibration of a compressor.

[0003] 2. Description of the Related Art

[0004] In general, in a piston type compressor such as a swash plate type compressor, an intake chamber and a discharge chamber are partitioned from each other by means of a partitioning wall in a housing, and a cylinder block is disposed so as to face these intake chamber and discharge chamber while intervening a valve plate therebetween. Pistons are disposed slidably within cylinder bores formed in the cylinder block. When the pistons are reciprocated in accordance with the rotation of a rotary shaft, refrigerant within the intake chamber is sucked into the cylinder bore and at the same time, refrigerant is discharged from the cylinder bore.

[0005] However, in the case where carbon dioxide is used as refrigerant or the like, the refrigerant is used under the rather high-pressure condition. As a result, there is a problem in that large vibration is liable to be generated in accordance with the compression of the refrigerant.

[0006] In order to reduce the vibration, if the rigidity of the housing of the compressor is enhanced, the thickness of the housing is increased with the result that the weight of the compressor is increased.

SUMMARY OF THE INVENTION

[0007] In order to overcome such a problem, an object of the present invention is to provide a compressor capable of reducing the vibration during the operation while suppressing the increase in the weight.

[0008] In the compressor in accordance with the present invention, a hollow projection portion is formed in a housing, a bearing for rotatably supporting an end portion of a rotary shaft within this projection portion, and furthermore, an attaching leg portion is formed on an outer surface of the projection portion.

[0009] A bearing is disposed within the hollow projection portion so that the rigidity of the bearing portion is increased even if the thickness of the housing is not increased, and furthermore, the attaching leg portion is formed on the outer surface of the projection portion, i.e., in the vicinity of the bearing to thereby effectively reduce the vibration.

[0010] Note that, the housing is composed of a front housing and a rear housing to be bonded together and the hollow projection portion is formed in the rear housing, whereas the intake chamber and the discharge chamber are defined in the interior of the front housing and at the same time, another attaching leg portions may be formed on the outer surface of the front housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a side elevational cross-sectional view showing a structure of a swash plate type variable capacity compressor in accordance with an embodiment of the present invention; and

[0012]FIG. 2 is a plan view showing the compressor shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0014]FIG. 1 shows a structure of a swash plate type variable capacity compressor in accordance with an embodiment of this invention. A front housing 1 and a rear housing 2 are fastened together by means of bolts 4 under the condition that they are coupled with each other through a gasket 3 to thereby form a whole housing 5. A stepped portion 6 is formed within the front housing 1. A retainer forming plate 7, a valve forming plate 8, a valve plate 9 and a valve forming plate 10 are fitted so as to be jointed to this stepped portion 6. An intake chamber 12 and a discharge chamber 13 are defined between the retainer forming plate 7 and a rear end wall portion 11 of the front housing 1 so as to be apart from each other through a partitioning wall 14.

[0015] Also, a cylinder block 15 is fitted so as to be jointed to the valve forming plate 10 within the front housing 1 and is fixed to the front housing 1 with bolts 16. A rotary shaft 17 is rotatably supported by the cylinder block 15, the front housing 1 and the rear housing 2. The front end of the rotary shaft 17 projects from the front housing 1 to the outside and is connected to unillustrated rotational drive source such as an automotive engine or a motor or the like. A rotary support member 18 is fixed to the rotary shaft 17 within the rear housing 2 and a swash plate 19 is provided so as to engage with the rotary support member 18. A pair of guide pins 20 formed in and projecting from the swash plate 19 are slidably fitted into a pair of guide holes 21 formed in the rotary support member 18 under the condition that the rotary shaft 17 passes through the through-hole formed in the central portion of the swash plate 19. The swash plate 18 is rotated together with the rotary shaft 17 and supported such that it may be slid and tilted in the axial direction of the rotary shaft 17 by means of the engagement of the guide pin 20 with the guide hole 21. Also, the rotary support member 18 is rotatably supported by a thrust bearing 22 which is arranged in the rear end inner wall portion of the rear housing 2.

[0016] A plurality of cylinder bores 23 are arranged around the rotary shaft 17 in the cylinder block 15. A piston 24 is slidably received in each cylinder bore 23. Each piston 24 is engaged with an outer circumferential portion of the swash plate 19 through a pair of shoes 25. When the swash plate 19 rotates together with the rotary shaft 17, each piston 24 performs reciprocating motion through the shoe 25 in the axial direction of the rotary shaft 17 within the cylinder bore 23.

[0017] A hollow projection portion 26 is formed in a rear end portion of the rear housing 2. A bearing 27 is disposed for rotatably supporting a rear end portion of the rotary shaft 17 in the interior of the projection portion 26. Furthermore, an attaching leg portion 28 is formed on the outer surface of the projection portion 26. The attaching leg portion 28 is used for mounting the compressor, by passing a bolt or the like through a through-hole 29 formed along its centerline, to an engine block, a bracket or the like. Attaching leg portions 30 and 31, similar to the attaching leg portion 26, are formed on an upper outer surface and a lower outer surface of the front housing 1, respectively. As shown in FIG. 2, each of the attaching leg portions 28, 30 and 31 have a shape that is long in its centerline direction.

[0018] During operation, the refrigerant within the intake chamber 12 flows into the cylinder bore 23 after passing through the intake port of the valve plate 9 and then pushing its way through the intake reed valve portion of the valve forming plate 10 in accordance with the return motion of the piston 24, i.e., the rearward movement thereof within the cylinder bore 23. This refrigerant is discharged to the discharge chamber 13 after passing through the discharge port of the valve plate 9 and then pushing its way through the discharge reed valve portion of the valve forming plate 8 in accordance with the subsequent advance motion of the piston 24, i.e., the forward movement thereof within the cylinder bore 23.

[0019] At this time, the compression load of the refrigerant based upon the reciprocating motion of the piston 24 is transferred to the bearing 27 through the rotary shaft 17. However, the bearing 27 is contained in the projection portion 26 so that the rigidity of this portion is increased, and furthermore, since the attaching leg portion 28 is provided on the outer surface of the projection portion 26, i.e., immediately close to the bearing 27, the attaching leg portion 28 is fastened to, for example, the engine block to thereby make it possible to effectively reduce the vibration during the operation.

[0020] Although the attaching leg portions 28, 30 and 31 are fastened to the engine block, the bracket or the like by means of bolts or the like, in order to reduce the vibration, it is preferable to fasten the portions to the engine block, which has a large weight.

[0021] As described above, according to the present invention, since the bearing for rotatably supporting the end portion of the rotary shaft is disposed within the hollow projection portion of the housing and the attaching leg portion is formed on the outer surface of the projection portion, it is possible to effectively reduce the vibration during the operation while suppressing the increase in the weight.

[0022] Accordingly, the present invention is effectively applied to a compressor that is to be used under the high pressure condition in the case where the carbon dioxide is used as the refrigerant and so on. 

What is claimed is:
 1. A compressor comprising: a housing having a hollow projection portion; a rotary shaft provided rotatably within said housing; a piston reciprocating in accordance with rotation of said rotary shaft for sucking and discharging fluid; a bearing disposed within the projection portion of said housing for rotatably supporting one end of said rotary shaft; and an attaching leg portion formed on an outer surface of the projection portion of said housing.
 2. A compressor according to claim 1 wherein said housing comprises: a front housing in which an intake chamber and a discharge chamber are formed therein and another leg portions are formed on an outer surface thereof; and a rear housing to be bonded to said front housing in which the hollow projection portion is formed.
 3. The compressor according to claim 1 wherein said attaching leg portion has a shape that is long in its centerline direction. 